论文标题
关于磁通管的上升和深域中黑子的形成
On rising magnetic flux tube and formation of sunspots in a deep domain
论文作者
论文摘要
我们研究了前所未有的深度计算结构域中的上升通量管和黑子的形成，该域覆盖了整个对流区，并具有辐射的磁性水力动力学模拟。先前的计算具有浅的计算箱（<30 mm）和对流区，深度为200 mm。通过使用我们的新数值R2D2，我们成功地覆盖了整个对流区，并从简单的水平通量管中重现了黑子的形成，因为湍流的热对流。主要发现是（1）由于磁性压力和混合的抑制作用引起的低密度，通量管的上升速度大于向上的速度。 （2）在18 mm的深度下，通量管的上升速度超过250 m/s，而在太阳表面出现之前，我们看不到3小时的流动流量的明确证据。 （3）最初，通量管的根部充满了下流，然后在黑子形成期间，上流填充了通量管的中心。 （4）晒黑形成的基本机制是相干的流入和湍流运输。 （5）低温区域在成熟的黑子中至少延伸至至少40毫米的深度，并在通量管中心的高温区域。一些发现表明，深度计算域对磁通出现模拟的重要性。
We investigate the rising flux tube and the formation of sunspots in an unprecedentedly deep computational domain that covers the whole convection zone with a radiative magnetohydrodynamics simulation. Previous calculations had shallow computational boxes (< 30 Mm) and convection zones at a depth of 200 Mm. By using our new numerical code R2D2, we succeed in covering the whole convection zone and reproduce the formation of the sunspot from a simple horizontal flux tube because of the turbulent thermal convection. The main findings are (1) The rising speed of the flux tube is larger than the upward convection velocity because of the low density caused by the magnetic pressure and the suppression of the mixing. (2) The rising speed of the flux tube exceeds 250 m/s at a depth of 18 Mm, while we do not see any clear evidence of the divergent flow 3 hr before the emergence at the solar surface. (3) Initially, the root of the flux tube is filled with the downflows and then the upflow fills the center of the flux tube during the formation of the sunspot. (4) The essential mechanisms for the formation of the sunspot are the coherent inflow and the turbulent transport. (5) The low-temperature region is extended to a depth of at least 40 Mm in the matured sunspot, with the high-temperature region in the center of the flux tube. Some of the findings indicate the importance of the deep computational domain for the flux emergence simulations.
